159
FXUS65 KBYZ 161147
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
547 AM MDT THU APR 16 2026
KEY MESSAGES
- STORM SYSTEM TONIGHT INTO FRIDAY: WIDESPREAD RAIN TRANSITIONING
TO SNOW DURING THE DAY TODAY. SNOW ACCUMULATIONS CONFINED TO
THE FOOTHILLS.
- MODERATE TO HEAVY SNOW FOR ALL MOUNTAINS.
- WARMER AND DRY THIS WEEKEND.
- ACTIVE WEATHER CONTINUES NEXT WEEK.
UPDATE
A FEW CHANGES TO THE FORECAST THIS MORNING. COLD FRONT HAS PUSHED
TO A MILES CITY TO ASHLAND LINE AT 430 AM. A DEFINED BAND OF
PRECIPITATION HAS DEVELOPED ALONG THE 700MB FRONTOGENESIS LINE
OVER EASTERN YELLOWSTONE COUNTY, SHIFTING SLOWLY TO THE EAST AS
COLDER AIR DEEPENS UP. UPDATED FORECAST HIGHS TO GO ABOUT 5
DEGREES COOLER THAN PREVIOUS FORECAST. TEMPERATURES ARE FALLING
QUICKLY BEHIND THE COLD FRONT AND WITH CLOUD COVER AND
PRECIPITATION ALL DAY EXPECT HIGHS TO STICK FAIRLY CLOSE TO EARLY
MORNING READINGS THROUGH THE DAY. ALSO ADJUSTED PRECIPITATION
PROBABILITIES FOR THE LATEST MODEL TRENDS, AND TWEAKED THE
PRECIPITATION TYPE TOWARD MORE SNOW AS CHANGE OVER IS HAPPENING
MUCH FASTER THAN MOST MODELS ARE ADVERTISING. KEPT SNOW AND
PRECIPITATION AMOUNTS PRETTY CLOSE TO PREVIOUS FORECAST,
ACCOUNTING FOR WHAT HAS ALREADY OCCURRED OVERNIGHT. NO CHANGES TO
THE GOING WINTER WEATHER HIGHLITES AT THIS TIME. CHAMBERS
DISCUSSION
THROUGH WEDNESDAY...
THE LONGWAVE TROUGH IS DIGGING INTO THE INTERMOUNTAIN WEST NOW AND
PUSHING A SURFACE THROUGH NORTHERN MT. THE TRAILING COLD FRONT IS
ALREADY ENTERING THE WESTERN PART OF THE CWA AT THIS TIME. EXPECT
A STARK WIND SHIFT TO THE NW AND TEMPS TO RAPIDLY COOL BEHIND THE
FRONTAL PUSH.
JUST AHEAD OF THE FROPA THERE IS SOME SIGNAL FOR MOUNTAIN WAVE
ACTIVITY IN THE FOOTHILLS NEAR RED LODGE. THE TIMBERCREST STATION
JUST ABOVE THE CITY IS ALREADY SEEING SOME WIND GUSTS INTO THE 40S
MPH. THE WAVES SHOULD NOT BE STRONG DUE TO THE 700MB FLOW ONLY
BEING AROUND 40 TO 50 KTS. THAT BEING SAID THOUGH, THE FLOW OF
THE 700MB WINDS ARE PERPENDICULAR TO THE NE FACE OF THE
BEARTOOTH/ABSAROKAS. ADDITIONALLY, THE SUBSIDENCE AHEAD OF THE
FRONT IS VERY PRONOUNCED AND SHOULD BE ABLE TO FORCE DOWN SOME
WIND GUSTS WITH ASSISTANCE OF THE STABLE LAYER FORECAST TO SET UP
JUST AT THE MOUNTAINTOPS. SOME MEMBERS OF THE HREF (PRIMARILY THE
HRW) DO BRING 50 TO 60 MPH GUSTS INTO RED LODGE, HOWEVER, IT
APPEARS THAT 40 MPH GUSTS ARE MORE LIKELY. THAT IS NOT TO SAY THAT
A STRAY GUST OFF A PARTICULARLY HIGH AMPLITUDE AND STRONG WAVE
COULD NOT TOUCH THE 50S MPH. THE SETUP FOR THE EAST SIDE OF THE
BIGHORNS (SHERIDAN, WY) IS SLIGHTLY LESS FAVORABLE FOR THE
DEVELOPMENT OF ANY WAVES. THE 700MB WIND WILL BE TOO
SOUTHWESTERLY AND NOT STRONG ENOUGH. THERE STILL WIL BE STRONG
SUBSIDENCE SO A GUST INTO THE 30S MPH AHEAD OF THE FROPA THIS
MORNING IS NOT OUT OF THE QUESTION IN THE IMMEDIATE FOOTHILLS.
TURNING THE ATTENTION OVER TO THE PRECIPITATION, WE ARE ALREADY
SEEING A GOOD AMOUNT OF PRE-FRONTAL SHOWERS ACROSS THE WESTERN
HALF OF THE CWA JUST DUE TO CVA AHEAD OF THE POTENT TROUGH. AS THE
FRONT PUSHES THROUGH, THE PRECIPITATION WILL BECOME MUCH MORE
WIDESPREAD THIS MORNING. TEMPERATURES, AND THEREFORE SNOW LEVELS,
ARE FORECAST TO QUICKLY DROP DURING THE DAY TODAY. WHILE MOST OF
THE REGION HAS SNOW LEVELS AROUND 6 KFT AT TIS TIME, BY NOON THE
WESTERN 2/3 OF THE CWA SHOULD BE SEEING SNOW AS THE PREDOMINAT
FORM OF PRECIP WITH THE WHOLE AREA SEEING SNOW BY THIS EVENING.
WITH HOW WARM WE HAVE BEEN OVER THE PAST WEEK OR SO, IT WILL BE
QUITE HARD FOR THIS SNOW TO ACCUMULATE UNLESS IT IS COMING DOWN
PARTICULARLY HEAVY AND/OR FOR AN EXTENDED PERIOD OF TIME. THIS IS
WHY THE ACCUMULATION SHOULD BE LIMITED TO THE MOUNTAINS AND
FOOTHILLS.
OVER THE PAST 24 HOURS THE SNOW AND PRECIP TOTALS HAVE REMAINED
RELATIVELY STEADY. WHAT HAS CHANGED A LITTLE BIT IS THE HIGH END
AMOUNTS FOR MOST OF THE FOOTHILLS HAVE COME DOWN. THIS JUST
APPEARS TO BE DUE TO THE MODELS COMING INTO BETTER AGREEMENT THAT
THE SURFACE WINDS SHOULD NOT SHIFT EAST OF NORTH. THIS SETUP IS
NOT FAVORABLE FOR LOCATIONS LIKE THE FOOTHILLS WEST OF SHERIDAN,
WY BUT WEAK ENHANCEMENT COULD STILL PRODUCE 1-3" TOTALS WITH
LOCALIZED HIGHER AMOUNTS; ESPECIALLY NEAR STORY. THESE NORTH-
NORTHWESTERLY WINDS ARE NOT ALL BAD NEWS FOR THE SNOW LOVERS
THOUGH. SOME LOCATIONS CAN STIL GET GOOD UPSLOPE WITH THIS FLOW
INCLUDING THE PARADISE VALLEY. WHILE MODELS STILL DISAGREE A
COUPLE 10S OF DEGREES ON WIND DIRECTION, THERE IS A CONSENSUS THAT
SOME FORM OF NORTHERLY COMPONENT OF WIND WILL BLOW UP THE VALLEY
THURSDAY AFTERNOON AND EVENING. DUE TO THE WESTERLY COMPONENT
THOUGH, IT APPEARS THAT LOCATIONS EAST OF US-89 WILL LIKELY PICK
UP FAR MORE SNOW THAN AREAS TO THE WEST. THIS TYPE OF SETUP COULD
RESULT IN VERY LOCALIZED AREAS OF HEAVIER SNOW IN PLACES LIKE PINE
CREEK OR CHICO WHERE THE NBM 90TH SHOWS 10" TOTALS. RED LODGE
ALSO WILL NOT BE COMPLETELY SKIPPED BY THIS UPSLOPE EITHER. WHILE
NOT AS FAVORABLE AS A NNE WIND, THE PRIMARILY NORTHERLY COMPONENT
WILL STILL MEAN THAT THERE WILL BE UPSLOPE WINDS INTO THE AREA. SO
WHILE THE 90TH PERCENTILE IS NO LONGER 11" AS IT WAS SHOWING
YESTERDAY, THE TOWN OF RED LODGE COULD PICK UP 5" WHEN THIS IS ALL
SAID AND DONE. IT IS ALSO WORTH NOTING THAT DUE TO THE COMPLEX
TERRAIN WEST OF BILLINGS, SOME LOCALES MAY SEE AN INCH OR TWO MORE
THAN THE ADVERTISED FORECAST WHILE SOME MAY SEE AN INCH OR TWO
LESS WITH THESE DIFFERENCES POTENTLY WITHIN A FEW MILES OF EACH
OTHER.
THE OTHER CONCERN WITH THE SNOW WILL BE THE POTENTIALLY REDUCED
VISIBILITY DUE TO BLOWING SNOW AS IT FALLS. THE GREATEST AREAS OF
CONCERN WOULD BE SHERIDAN CO. WY, PARTICULARLY SOUTH OF THE CITY
OF SHERIDAN, AND SE CARBON CO. MT NAR BELFRY. BOTH OF THESE AREAS
ARE IN LOCATIONS FAVORABLE TO SEE ENHANCEMENT OF THE WINDS DUE TO
WIND'S ORIENTATION IN RELATION WITH THE SURROUNDING TERRAIN. THE
FORECAST WIND GUSTS HAVE COME DOWN A BIT OVER THE PAST FEW RUNS TO
WHERE OUR OFFICIAL FORECAST IS NOW ADVERTISING GUSTS IN THE LOW
30S MPH WHICH WILL LIMIT ANY VISIBILITY REDUCTIONS. ALSO THE SNOW
WILL PROBABLY BE ON THE HEAVIER SIDE (LESS THAN 10:1) WHICH
SHOULD LIMIT ANY BLOWING AS WELL. THAT BEING SAID, PREPARE FOR
REDUCTIONS IN VISIBILITY IN THESE AREAS TONIGHT.
AFTER THIS SYSTEM EXITS DURING THE DAY FRIDAY, RIDGING QUICKLY
BUILDS BACK INTO THE ENTIRE INTERMOUNTAIN WEST. THIS WILL ALLOW
FOR TEMPERATURES TO QUICKLY REBOUND BACK TO ABOVE AVERAGE FOR THE
ENTIRE WEEKEND AS WELL AS KEEP THE ENTIRE REGION DRY. WITH THESE
WARM TEMPERATURES, EXPECT ANY SNOW THAT ACCUMULATES OUTSIDE THE
MOUNTAINS (BELOW 6 KFT) TO QUICKLY MELT. BY SUNDAY, THE HIGH
TEMPERATURES FOR LOCATIONS NEAR BILLINGS MAY BE BACK IN THE 70S
AGAIN.
LOOKING AHEAD TO THE MIDDLE OF NEXT WEEK, ALL MODELS AND THEIR
ENSEMBLES CONTINUE TO SHOW A HIGH AMPLITUDE TROUGH DIG INTO THE
WEST COAST. THERE IS STILL DISAGREEMENT AROUND WHAT THIS WILL LOOK
LIKE (IE. CUTOFF OR PROGRESSIVE) BUT IT IS SAFE TO SAY THAT
ANOTHER POTENTIALLY IMPACTFUL SYSTEM COULD BE HERE BY THIS TIME
NEXT WEEK. WMR
AVIATION
12Z TAF DISCUSSION...COLD FRONT IS WORKING THROUGH SE MONTANA
EARLY THIS MORNING WITH A PRONOUNCED BAND OF PRECIPITATION
TRAILING BEHIND IT. SNOW IS FALLING DOWN TO AROUND 4500 FEET MSL.
EXPECT SNOW LEVELS TO DROP TO AROUND 3000 FEET MSL BY LATE
AFTERNOON, STICKING AROUND THAT ELEVATION THROUGH FRIDAY. EXPECT
GUSTY NORTHWEST WINDS OF 20 TO 30KTS THROUGH EARLY THIS EVENING.
TAFS ARE TRICKY THIS MORNING WITH MODELS SHOWING DIFFERING
SOLUTIONS DUE TO A SPLITTING TROF PUTTING PRECIPITATION IN
DIFFERENT AREAS ALONG WITH DIFFERING WIND FIELDS THAT IN SOME
CASES BRINGS A LOT LESS PRECIPITATION THAN OTHERS. 12Z TAFS LEAN
ON THE RAP SOLUTION THAT HAS DONE THE BEST SO FAR THIS MORNING
WITH THE FRONTAL PASSAGE, WINDS, AND PRECIPITATION BUT ALSO TRIES
TO TAKE INTO ACCOUNT THE BROADER GFS/NBM THOUGHTS.
EXPECT PERIODS OF MVFR TO IFR CONDITIONS WITH PRECIPITATION. A
SHIFT TO A MORE NORTHERLY WIND DIRECTION (POSSIBLY MORE
NORTHEASTERLY) ARRIVING BETWEEN 16 AND 22Z HAS A GOOD PROBABILITY
OF INCREASING PRECIPITATION COVERAGE AND LOWERING CEILINGS TO MORE
WIDESPREAD IFR/LIFR. ANY BREAKS IN THE WIND THIS AFTERNOON WILL
ALSO INCREASE THE POTENTIAL FOR FOG DEVELOPMENT TO FURTHER IMPACT
FLIGHT CONDITIONS. FOOTHILLS/MOUNTAIN SNOWFALL WILL CONTINUE INTO
TONIGHT. EXPECT CONTINUED MOUNTAIN AND PASS OBSCURATION THROUGH
TONIGHT. FLIGHT CONDITIONS ACROSS THE NORTHERN TIER OF THE
FORECAST AREA WILL IMPROVE BY MID EVENING THROUGH THE REST OF
TONIGHT. CHAMBERS
PRELIMINARY POINT TEMP/POPS
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 041 026/049 028/060 034/072 043/078 045/080 048/072
9/O 54/J 20/U 00/U 00/B 01/U 24/W
LVM 035 021/042 021/056 030/067 037/072 042/074 043/064
8/S 57/T 30/U 00/U 00/B 12/W 35/W
HDN 043 023/050 026/061 031/073 038/079 042/082 047/075
8/O 54/J 20/U 00/U 00/B 11/U 24/W
MLS 045 023/042 023/055 030/070 040/076 043/080 049/072
4/O 20/B 00/B 00/U 00/U 00/U 13/W
4BQ 051 025/043 024/054 030/069 040/077 044/080 048/073
7/R 71/B 00/B 00/U 00/U 00/U 23/W
BHK 051 022/038 018/050 025/066 037/073 040/075 044/069
4/R 51/N 00/B 00/U 00/U 00/U 13/W
SHR 045 021/042 021/054 028/067 035/075 041/077 043/071
9/T 96/J 31/U 00/U 00/B 11/U 24/W
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MDT FRIDAY FOR
ZONES 40-56-64>66.
WINTER STORM WARNING IN EFFECT UNTIL 6 AM MDT FRIDAY FOR
ZONES 67-68.
WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO 6 AM MDT
FRIDAY FOR ZONE 138.
WINTER WEATHER ADVISORY IN EFFECT FROM 9 AM THIS MORNING TO 6
AM MDT FRIDAY FOR ZONE 171.
WY...WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO 6 AM MDT
FRIDAY FOR ZONE 199.
WINTER WEATHER ADVISORY IN EFFECT FROM 9 AM THIS MORNING TO 6
AM MDT FRIDAY FOR ZONE 198.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page